diff --git a/codegen/src/lib.rs b/codegen/src/lib.rs
index 4ab0f628..d985757b 100644
--- a/codegen/src/lib.rs
+++ b/codegen/src/lib.rs
@@ -339,10 +339,10 @@ pub fn set_exported_fn(args: proc_macro::TokenStream) -> proc_macro::TokenStream
             let param_names = quote! { None };
 
             proc_macro::TokenStream::from(quote! {
-                #module_expr.set_plugin_fn(#export_name, FnNamespace::Internal, FnAccess::Public,
-                                           #param_names,
-                                           &#gen_mod_path::Token::param_types(),
-                                           #gen_mod_path::Token());
+                #module_expr.set_fn(#export_name, FnNamespace::Internal, FnAccess::Public,
+                                    #param_names,
+                                    &#gen_mod_path::Token::param_types(),
+                                    #gen_mod_path::Token().into());
             })
         }
         Err(e) => e.to_compile_error().into(),
@@ -388,10 +388,10 @@ pub fn set_exported_global_fn(args: proc_macro::TokenStream) -> proc_macro::Toke
             let param_names = quote! { None };
 
             proc_macro::TokenStream::from(quote! {
-                #module_expr.set_plugin_fn(#export_name, FnNamespace::Global, FnAccess::Public,
-                                           #param_names,
-                                           &#gen_mod_path::Token::param_types(),
-                                           #gen_mod_path::Token());
+                #module_expr.set_fn(#export_name, FnNamespace::Global, FnAccess::Public,
+                                    #param_names,
+                                    &#gen_mod_path::Token::param_types(),
+                                    #gen_mod_path::Token().into());
             })
         }
         Err(e) => e.to_compile_error().into(),
diff --git a/codegen/src/rhai_module.rs b/codegen/src/rhai_module.rs
index c21384aa..1fafd99e 100644
--- a/codegen/src/rhai_module.rs
+++ b/codegen/src/rhai_module.rs
@@ -164,8 +164,8 @@ pub fn generate_body(
 
             set_fn_statements.push(
                 syn::parse2::<syn::Stmt>(quote! {
-                    m.set_plugin_fn(#fn_literal, FnNamespace::#ns_str, FnAccess::Public,
-                                    #param_names, &[#(#fn_input_types),*], #fn_token_name());
+                    m.set_fn(#fn_literal, FnNamespace::#ns_str, FnAccess::Public,
+                             #param_names, &[#(#fn_input_types),*], #fn_token_name().into());
                 })
                 .unwrap(),
             );
diff --git a/codegen/src/test/module.rs b/codegen/src/test/module.rs
index 22f75fdf..fdf4cf12 100644
--- a/codegen/src/test/module.rs
+++ b/codegen/src/test/module.rs
@@ -297,9 +297,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("get_mystic_number", FnNamespace::Internal, FnAccess::Public,
+                    m.set_fn("get_mystic_number", FnNamespace::Internal, FnAccess::Public,
                              Some(get_mystic_number_token::PARAM_NAMES), &[],
-                             get_mystic_number_token());
+                             get_mystic_number_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -351,9 +351,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("add_one_to", FnNamespace::Global, FnAccess::Public,
+                    m.set_fn("add_one_to", FnNamespace::Global, FnAccess::Public,
                              Some(add_one_to_token::PARAM_NAMES), &[TypeId::of::<INT>()],
-                             add_one_to_token());
+                             add_one_to_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -405,9 +405,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("add_one_to", FnNamespace::Internal, FnAccess::Public, Some(add_one_to_token::PARAM_NAMES),
+                    m.set_fn("add_one_to", FnNamespace::Internal, FnAccess::Public, Some(add_one_to_token::PARAM_NAMES),
                              &[TypeId::of::<INT>()],
-                             add_one_to_token());
+                             add_one_to_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -470,12 +470,12 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("add_n", FnNamespace::Internal, FnAccess::Public, Some(add_one_to_token::PARAM_NAMES),
+                    m.set_fn("add_n", FnNamespace::Internal, FnAccess::Public, Some(add_one_to_token::PARAM_NAMES),
                              &[TypeId::of::<INT>()],
-                             add_one_to_token());
-                    m.set_plugin_fn("add_n", FnNamespace::Internal, FnAccess::Public, Some(add_n_to_token::PARAM_NAMES),
+                             add_one_to_token().into());
+                    m.set_fn("add_n", FnNamespace::Internal, FnAccess::Public, Some(add_n_to_token::PARAM_NAMES),
                              &[TypeId::of::<INT>(), TypeId::of::<INT>()],
-                             add_n_to_token());
+                             add_n_to_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -545,9 +545,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("add_together", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
+                    m.set_fn("add_together", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
                              &[TypeId::of::<INT>(), TypeId::of::<INT>()],
-                             add_together_token());
+                             add_together_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -601,15 +601,15 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("add", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
+                    m.set_fn("add", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
                              &[TypeId::of::<INT>(), TypeId::of::<INT>()],
-                             add_together_token());
-                    m.set_plugin_fn("+", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
+                             add_together_token().into());
+                    m.set_fn("+", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
                              &[TypeId::of::<INT>(), TypeId::of::<INT>()],
-                             add_together_token());
-                    m.set_plugin_fn("add_together", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
+                             add_together_token().into());
+                    m.set_fn("add_together", FnNamespace::Internal, FnAccess::Public, Some(add_together_token::PARAM_NAMES),
                              &[TypeId::of::<INT>(), TypeId::of::<INT>()],
-                             add_together_token());
+                             add_together_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -844,9 +844,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("get_mystic_number", FnNamespace::Internal, FnAccess::Public,
+                    m.set_fn("get_mystic_number", FnNamespace::Internal, FnAccess::Public,
                              Some(get_mystic_number_token::PARAM_NAMES), &[],
-                             get_mystic_number_token());
+                             get_mystic_number_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -928,9 +928,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("print_out_to", FnNamespace::Internal, FnAccess::Public, Some(print_out_to_token::PARAM_NAMES),
+                    m.set_fn("print_out_to", FnNamespace::Internal, FnAccess::Public, Some(print_out_to_token::PARAM_NAMES),
                              &[TypeId::of::<ImmutableString>()],
-                             print_out_to_token());
+                             print_out_to_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -982,9 +982,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("print_out_to", FnNamespace::Internal, FnAccess::Public, Some(print_out_to_token::PARAM_NAMES),
+                    m.set_fn("print_out_to", FnNamespace::Internal, FnAccess::Public, Some(print_out_to_token::PARAM_NAMES),
                              &[TypeId::of::<ImmutableString>()],
-                             print_out_to_token());
+                             print_out_to_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1037,9 +1037,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("foo", FnNamespace::Internal, FnAccess::Public, Some(foo_token::PARAM_NAMES),
+                    m.set_fn("foo", FnNamespace::Internal, FnAccess::Public, Some(foo_token::PARAM_NAMES),
                              &[TypeId::of::<FLOAT>(), TypeId::of::<INT>()],
-                             foo_token());
+                             foo_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1092,9 +1092,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
+                    m.set_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
                              &[TypeId::of::<FLOAT>()],
-                             increment_token());
+                             increment_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1154,9 +1154,9 @@ mod generate_tests {
                     }
                     #[allow(unused_mut)]
                     pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                        m.set_plugin_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
+                        m.set_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
                                  &[TypeId::of::<FLOAT>()],
-                                 increment_token());
+                                 increment_token().into());
                         if flatten {} else {}
                     }
                     #[allow(non_camel_case_types)]
@@ -1237,9 +1237,9 @@ mod generate_tests {
                     }
                     #[allow(unused_mut)]
                     pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                        m.set_plugin_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
+                        m.set_fn("increment", FnNamespace::Internal, FnAccess::Public, Some(increment_token::PARAM_NAMES),
                                  &[TypeId::of::<FLOAT>()],
-                                 increment_token());
+                                 increment_token().into());
                         if flatten {} else {}
                     }
                     #[allow(non_camel_case_types)]
@@ -1319,9 +1319,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("get$square", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                    m.set_fn("get$square", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>()],
-                             int_foo_token());
+                             int_foo_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1379,12 +1379,12 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("square", FnNamespace::Internal, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                    m.set_fn("square", FnNamespace::Internal, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>()],
-                             int_foo_token());
-                    m.set_plugin_fn("get$square", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                             int_foo_token().into());
+                    m.set_fn("get$square", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>()],
-                             int_foo_token());
+                             int_foo_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1442,9 +1442,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("set$squared", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                    m.set_fn("set$squared", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>(), TypeId::of::<u64>()],
-                             int_foo_token());
+                             int_foo_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1503,12 +1503,12 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("set_sq", FnNamespace::Internal, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                    m.set_fn("set_sq", FnNamespace::Internal, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>(), TypeId::of::<u64>()],
-                             int_foo_token());
-                    m.set_plugin_fn("set$squared", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
+                             int_foo_token().into());
+                    m.set_fn("set$squared", FnNamespace::Global, FnAccess::Public, Some(int_foo_token::PARAM_NAMES),
                              &[TypeId::of::<u64>(), TypeId::of::<u64>()],
-                             int_foo_token());
+                             int_foo_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1567,9 +1567,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("index$get$", FnNamespace::Global, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
+                    m.set_fn("index$get$", FnNamespace::Global, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>()],
-                             get_by_index_token());
+                             get_by_index_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1628,12 +1628,12 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("get", FnNamespace::Internal, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
+                    m.set_fn("get", FnNamespace::Internal, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>()],
-                             get_by_index_token());
-                    m.set_plugin_fn("index$get$", FnNamespace::Global, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
+                             get_by_index_token().into());
+                    m.set_fn("index$get$", FnNamespace::Global, FnAccess::Public, Some(get_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>()],
-                             get_by_index_token());
+                             get_by_index_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1692,9 +1692,9 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("index$set$", FnNamespace::Global, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
+                    m.set_fn("index$set$", FnNamespace::Global, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>(), TypeId::of::<FLOAT>()],
-                             set_by_index_token());
+                             set_by_index_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
@@ -1754,12 +1754,12 @@ mod generate_tests {
                 }
                 #[allow(unused_mut)]
                 pub fn rhai_generate_into_module(m: &mut Module, flatten: bool) {
-                    m.set_plugin_fn("set", FnNamespace::Internal, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
+                    m.set_fn("set", FnNamespace::Internal, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>(), TypeId::of::<FLOAT>()],
-                             set_by_index_token());
-                    m.set_plugin_fn("index$set$", FnNamespace::Global, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
+                             set_by_index_token().into());
+                    m.set_fn("index$set$", FnNamespace::Global, FnAccess::Public, Some(set_by_index_token::PARAM_NAMES),
                              &[TypeId::of::<MyCollection>(), TypeId::of::<u64>(), TypeId::of::<FLOAT>()],
-                             set_by_index_token());
+                             set_by_index_token().into());
                     if flatten {} else {}
                 }
                 #[allow(non_camel_case_types)]
diff --git a/src/module/mod.rs b/src/module/mod.rs
index d10fa983..f3cf1812 100644
--- a/src/module/mod.rs
+++ b/src/module/mod.rs
@@ -718,61 +718,6 @@ impl Module {
         hash_fn
     }
 
-    /// Set a plugin function into the [`Module`], returning a hash key.
-    ///
-    /// If there is an existing Rust function of the same hash, it is replaced.
-    ///
-    /// # WARNING - Low Level API
-    ///
-    /// This function is very low level. It is intended for plugins system use only.
-    #[inline(always)]
-    pub fn set_plugin_fn(
-        &mut self,
-        name: impl AsRef<str> + Into<ImmutableString>,
-        namespace: FnNamespace,
-        access: FnAccess,
-        _arg_names: Option<&[&str]>,
-        arg_types: &[TypeId],
-        func: impl PluginFunction + SendSync + 'static,
-    ) -> u64 {
-        let is_method = func.is_method_call();
-
-        let param_types: StaticVec<_> = arg_types
-            .iter()
-            .cloned()
-            .enumerate()
-            .map(|(i, type_id)| Self::map_type(!is_method || i > 0, type_id))
-            .collect();
-
-        #[cfg(feature = "metadata")]
-        let param_names = _arg_names
-            .iter()
-            .flat_map(|p| p.iter())
-            .map(|&arg| self.interned_strings.get(arg))
-            .collect();
-
-        let hash_fn = calc_native_fn_hash(empty(), &name, &param_types);
-
-        self.functions.insert(
-            hash_fn,
-            Box::new(FuncInfo {
-                name: self.interned_strings.get(name),
-                namespace,
-                access,
-                params: param_types.len(),
-                param_types,
-                #[cfg(feature = "metadata")]
-                param_names,
-                func: func.into(),
-            }),
-        );
-
-        self.indexed = false;
-        self.contains_indexed_global_functions = false;
-
-        hash_fn
-    }
-
     /// Set a Rust function taking a reference to the scripting [`Engine`][crate::Engine],
     /// the current set of functions, plus a list of mutable [`Dynamic`] references
     /// into the [`Module`], returning a hash key.